A U.N.-backed court has found the Khmer Rouge's last two remaining leaders guilty of crimes against humanity, more than 40 years after the mass deaths by the infamous dictatorship.

The court handed down its ruling on Thursday in the Cambodian capital of Phnom Penh, according to Reuters, and sentenced the two defendants to life in prison. More than 2 million Cambodians died during the Khmer Rouge regime between 1975 and 1979.

The leaders on trial -- Nuon Chea, 88, known as "Brother Number Two" and former President Khieu Samphan, 83 -- were the remaining two of the original four leaders charged when the trial began in 2011, according to Al Jazeera. Former foreign minister Ieng Sary died in 2013 and his wife, Ieng Thirith, 82, is too sick to stand trial.

The mastermind behind the Khmer Rouge, "Brother Number One," Pol Pot, died in 1998. The ultra-Maoist group attempted to create an agrarian society devoid of capitalism.

Due to the extent of the charges, which included a 350-page indictment, the court decided to break up the trial and this ruling focuses on the Khmer Rouge's leadership decision to evict all citizens from the capital in 1975 and forcing them to work on collectivized farms, Al Jazeera reports.

The trial pertaining to the more serious charges of genocide, mass murder and torture began in late July, according to The Guardian. The charges of genocide pertain to "the mass killings of an estimated 100,000 to 500,000 ethnic Cham Muslims and 20,000 Vietnamese."

The Guardian reports that the trial may last until 2016 and some fear the accused will not live long enough to hear the verdicts, but the first stage of the complex trial is over. 

According to the New York Times, hundreds of survivors as well as the relatives of the deceased gathered at the courthouse to hear the verdict and expressed happiness with the trial's outcome.

"We have been waiting for this verdict for more than 30 years," said Norng Chan Phal, who was imprisoned at S-21 prison as a child. His parents were tortured and executed there.

Though happy with the verdict, he said he wanted to see the men denied a proper burial, according to the Times. "After they die, their bodies should be kept in the prison cells," he said.